1. Field of the Invention
The present invention relates to a computer program product, system, and method for replicating a source data set to a target data store.
2. Description of the Related Art
In replication systems, an initial full copy of the source data is copied to the target data before changes are replicated from the source to the target. The copied target data must be point-in-time consistent with the source data, such that no committed data is missed. The copied data must include every record in the source data set from the start to the end of the initial copy process. The replication process may log changes that occur during the initial copy process. If an application later rolls back a transaction made to the source data, such as deleting a record inserted by the transaction, the replication system must handle the reversal by processing a replication log.
One technique for creating the initial copy is for the replication system to obtain exclusive control of the source data set during the refresh or initial copy stage. However, this technique could adversely affect application access to the source data while the initial copy is made. The refresh operation to create the initial copy may take an extended period of time, depending on network speed and the performance of the target system. After the initial copy is made, the lock may be released and any further logged changes can be sent to the target data.
There is a need in the art for improved techniques for creating the initial copy of the source data to be replicated that has minimal impact on application access to the source data.